A number of clamping devices for shafts are known in the art. Burnham, U.S. Pat. No. 4,142,811, incorporated herein by reference, discloses a one-piece locking and releasing hub, which has a thrust-multiplying screw to expand or close slots during removal of assembly. See FIGS. 1, 2, and 3. Burnham discloses a collar with two slits, creating two pivot points. Great force must be applied to compress this collar. The Burnham apparatus may not be applicable to mechanisms in which the clamping force is low or moderate. Junkes, U.S. Pat. No. 5,044,816, incorporated herein by reference, discloses a pipe clip with shells in clip body, which has parallel recesses in pipe retention space sidewalls. Vanzee, U.S. Pat. No. 5,062,734, incorporated herein by reference, discloses a shaft-coupling device having a groove extending only partially into outer wall for allowing coupler to flex. See FIG. 1, details 50 and 90.
Garnett, U.S. Pat. No. 5,042,826, incorporated herein by reference, discloses a machine collet for mounting and centering tools, which has a single piece body formed with an integral resilient flexure having lands for gripping a tool shank. Garnett discloses a “flexure member” instead of three or four discrete hinge points. However, in Garnett, the flexure members create an opening that is smaller than the cylindrical object to be clamped. Therefore the displacement of the thick flexure member causes the clamping, and an external force, the action of a screw, releases the pressure. Entrup, U.S. Pat. No. 5,318,375, incorporated herein by reference, discloses an apparatus for coupling a sleeve to power take-off shaft, which consists of multiple splined hole and shaft, with two holes and locking surface. See FIGS. 5, 6, and 7. Zettl, U.S. Pat. No. 5,158,407, incorporated herein by reference, discloses a coupling for a modular tool system, which has a clamping ring of special cross section to apply an axial clamping force.
Awtar, Published U.S. patent application No. 2004/0037626A1, incorporated herein by reference, discloses a torque coupling for rotating shafts, which has a compliant support structure joined to a coupling portion, and another coupling portion joined to a structure and movable relative to former portion with pre-set degrees of freedom. Awtar discloses that cuts are made in a disk-like object to enhance flexibility, but the object is never cut through. These cuts are not used for the purpose of clamping a shaft, and their geometry does not lend them to that application. They are used in a three-dimensional way, to accommodate for shaft misalignment. Heldmann, U.S. Pat. No. 4,116,572, incorporated herein by reference, discloses a collar type shaft clamping device, which has a radial slot through a collar with a recess and coaxial aligned tapped opening on opposite sides of slot. See FIG. 1, detail 20. Neugart, U.S. Pat. No. 6,413,006, incorporated herein by reference, discloses a connection between slotted hollow shaft/sleeve and a shaft fitted into it has one or more slots, with at least one slot closed at both ends. See FIGS. 1 and 8, detail 7a. Nilsson, U.S. Pat. No. 4,565,464, incorporated herein by reference, discloses a clamping shaft-hub joint, which comprises two sets of radially and axially extending slots, closed by screws to tighten a joint.
Ruland, U.S. Pat. No. 4,428,697, incorporated herein by reference, discloses a coupling or collar for clamping to rotatable shaft, which comprises a C-shaped member having ends pulled together by screw, with a balancing hole at an intermediate portion. See FIGS. 1 and 3, details C and Ca, respectively. Nell, U.S. Pat. No. 5,857,800, incorporated herein by reference, discloses an annular shaft flange for various industries such as automotive, which has a C-shaped, symmetrical washer, which, when open, passes over a shaft and then closes together when located, before having its ends spot-welded and secured in position. See FIGS. 1, 2, 3, and 7. Nishikawa, U.S. Pat. No. 5,851,084, incorporated herein by reference, discloses an inner elastic split spacer for mounting a rotor, which comprises a twin flange arc-shaped major elastic segment to be slipped onto a shaft and another matching segment that is bolted to a major segment. Schott, U.S. Pat. No. 3,868,193, incorporated herein by reference, discloses a cylindrical shaft clamping collar formed singly or in halves with side flats to allow distortion onto a shaft surface. Ruland, U.S. Pat. No. 5,096,327, incorporated herein by reference, discloses a clamp collar assembly, which includes a screw for controlling relative distance between opposed ends of the collar to change relative diameters.
Schlanger, U.S. Pat. No. 5,810,503, incorporated herein by reference, discloses a clamping device, which includes a moving unit, which moves a clamping element along longitudinal axis of shaft from unlocking engagement to locking engagement with a shaft to clamp it between a clamping element and base. See FIGS. 2 to 5. Firth, U.S. Pat. No. 3,738,691, incorporated herein by reference, discloses a bushing comprising part of a shaft-mountable unit, which is fitted within a hub having a tapered bore. The bushing includes a shank having a flange at one end thereof. A longitudinal slot is formed within the shank and extends from adjacent the flange to the opposite end of the shank. A transverse, part-circumferential slot is formed in the shank adjacent the flange in communication with the longitudinal slot.
Eiland, U.S. Pat. No. 4,217,061, incorporated herein by reference, discloses an annular ring shaft coupling which has a circumferential slot defining spring arms, which can be clamped to shafts. Phillips, Jr., U.S. Pat. No. 3,466,922, incorporated herein by reference, discloses a die assembly. DaCunha, U.S. Pat. No. 6,840,701, incorporated herein by reference, discloses a clamping device for securing a timing pulley to drive shaft, which has a hub whose outer peripheral portion is secured to timing pulley, and whose inner bore receives drive shaft. Zugel, U.S. Pat. No. 3,917,424, incorporated herein by reference, discloses a shaft coupling clamping device, which has opposed members with arcuate inner surfaces and relatively moved by threaded studs. Previte, U.S. Pat. No. 4,207,668, incorporated herein by reference, discloses a gyroscope flexure suspension assembly, which uses radially disposed single axis flexure joints to hold separate cylindrical units together.
Crispell, U.S. Pat. No. 3,876,318, incorporated herein by reference, discloses a pre-stressed steel shaft collar, which is split with axially aligned threaded holes. Howard, U.S. Pat. No. 3,473,202, incorporated herein by reference, discloses a pre-stressed shaft-engaging collar. Tuns, U.S. Pat. No. 5,306,096, incorporated herein by reference, discloses an adjustable body-coupling to a cylindrical shaft, which has a transverse slot in the body forming flanges clamped by screws against shaft.